Local variability in growth and reproduction of Salix arctica in the High Arctic

• Published in: Polar Research
• Main Authors: Noémie Boulanger-Lapointe, Esther Lévesque, Claudia Baittinger, Niels M. Schmidt
• Format: Article in Journal/Newspaper
• Language: English
• Published: Norwegian Polar Institute 2016
• Subjects: Herbivory; nutrient; plant colonization; vegetation; shrub; water availability; Environmental sciences; GE1-350; Oceanography; GC1-1581; Arctic; Greenland; Cassiope tetragona; Climate change; East Greenland; Polar Research; Tundra; Zackenberg
• Online Access: https://doi.org/10.3402/polar.v35.24126; https://doaj.org/article/66282e9cb8664c9c963a63364c0cbf8f

Arctic terrestrial ecosystems are heterogeneous because of the strong influences of microtopography, soil moisture and snow accumulation on vegetation distribution. The interaction between local biotic and abiotic factors and global climate patterns will influence species responses to climate change. Salix arctica (Arctic willow) is a structuring species, ubiquitous and widespread, and as such is one of the most important shrub species in the High Arctic. In this study, we measured S. arctica reproductive effort, early establishment, survival and growth in the Zackenberg valley, north-east Greenland. We sampled four plant communities that varied with respect to snow conditions, soil moisture, nutrient content and plant composition. We found large variability in reproductive effort and success with total catkin density ranging from 0.6 to 66 catkins/m2 and seedling density from <1 to 101 seedlings/m2. There were also major differences in crown area increment (4–23 cm2/year) and stem radial growth (40–74 µm/year). The snowbed community, which experienced a recent reduction in snow cover, supported young populations with high reproductive effort, establishment and growth. Soil nutrient content and herbivore activity apparently did not strongly constrain plant reproduction and growth, but competition by Cassiope tetragona and low soil moisture may inhibit performance. Our results show that local environmental factors, such as snow accumulation, have a significant impact on tundra plant response to climate change and will affect the understanding of regional vegetation response to climate change.